Damage to an intervertebral disk can lead to abnormal play of the vertebrae contiguous to this disk. This play subjects the posterior articular processes to considerable stresses, generating very painful wear and tear of these processes and general instability of the spinal column.
Such instability can also result from an operation performed on a herniated intervertebral disk, which has entailed access to the disk, in other words a weakening of the ligament system of the articulation, or can result from certain cases of arthrosis which also subjects the posterior articulations to considerable and painful stresses.